A corpora



J. DE KONING.

GRINDING MACHINE.

APPLICATlON FILED MAR. 11, 1920.

1,363 ,194. Patented Dec. 21,1920.

2 SHEETS-SHEET l.

1. DE KONING.

GRINDING MACHINE.

APPLICATION FILED MAR. 1 1920 2 SHEETS-SHEET 2.

1,363,194. Patnted Dec. 21,1920.

iiiliiilllll IlllllllH I.

UNITED STATES P. TENT ()FFJCE.

JACOB DE KONIING, O}? GRAND RAPIDS, IvIIC'I-IIGAN, ASSIGNOR '10 GRAND RAPIDS GRINDING MACHINE COLIIPANY, OF GRAND RAPIDS, MICHIGAN, A CORPORA- TIDN OF MICHIGAN.

GRINDING-IVIACHINE.

To all whom it may concern.

Be it known that I, Jaooe Dn KONING, a citizen of the United States, residing at Grand Rapids, in the county of Kent and State of Michigan, have invented newand useful improvements in Grinding-hlaclnnes, of whirh the following is a speciiica'tiom The present invention relates to grinding machines, particularly such as are employed for grinding rotary cutting tools, as thread-cutting taps and the like; and its object is to provide a machine of that character whereby the outward faces of the tools flutes may be ground conveXly and in such manner as to provide a clearance between the tool and its work extending increasingly from the l'lutes cutting edge; and further, to provide such a machine whereby all the l'lutes may be ground uniformly; and further, to pro ide such a machlne whereby said faces may be tapered and such a clearance provided.

These and any other objects hereinafter appearing are attained by, andthe lnventlon finds preferable embodiment 1n, the structure or structures hereinafter particularly described and illustrated by the accompanying drawings, in which Figure 1 is a side view of a grinding machine, certain parts being shown in vertical section and certain parts being broken away;

Fig. 2 is a sectional view or parts thereoi taken on a plane corresponding to line 22 or Fig. 1;

Fig. 3 i an end view of parts oi? said ma chine;

Fig. l; is a transverse sectional new (en larged) of said parts taken on a plane cor responding to line %l of Figs. 1 and 2;

Fig. 5 is a view of parts of the said machine partly in section, illustrating the eii'ect oi the grinding operation; and

Fig. 6 is top plan view of a slightly modilied construction or the grinding machine.

In the embodiment of the invention chosen for illustration by the drawings and for detailed description in the body otthis specification, the grinding wheel 1 is ournaled at 2 on the machines body 3 and is driven by the pulley 1. The rotary tool to be ground-as the tap 5is secured, ro-

Serial No. 364,905.

tatably on its axis of operative rotation, to the tool-holder, designated generally -6, as by the fixed mandrel 7 and the aXiallv adustable mandrel 8 carried by the tool-Holder and engaging in bearings provided for this purpose in the ends 01 the tool. The toolholders upper member 50 is pivotally mounted at 9 on a support 10 which is swingably mounted at 11 on a block 12. This block is swingably mounted at 13 on a carrying member 11 on an axis transverse to that of the mounting 11, so that the block 12 and parts *arried thereby including the tool may be swung toward and away from the grinding face 15 of the grinding wheel, such swinging movement toward the grinding wheel being limited by the adjustable screw stop 16. The carrying member 11 is slidable on the body 3 of the machine in a split bearing 17, to move the tool toward and away from the grinding wheel, said member being clamped in desired position by a set screw havingthe handle 18, which screw is adapted to compress the bearing 17. The member 50 of the toolholder 6 is swung on the axis 9 and held in swung position by a screw 19 journaled in the tool-holder and threaded in a nut 20 pivotally mounted on the support 10. The tool-holder is adapted to hold rotary tools of different lengths by reason of the slidable mounting of the arm 21 01" the mandrel S on the rod 22 of the tool-holder, said arm being held against rotary movement on this rod by a keyway 22. The tool is held against rotation in one direction on the mandrels by a leaf spring 21 whose extremity abuts that side of the flute which is adjacent its cutting edge, and which springs over the outer face of the flutes as the tool is turned in the opposite direction. This spring is mounted on a bar 25 slidable in a bearing in the bracket 26 on the rod 22 and clamped in desired position by a set screw 27.

The machine is operated in the following manner: The rotary tool 5 is secured in the tool-holder by means of the mandrels T, 8, and the carrying member 1 1 is slid in its bearing 1'7 to the position required for grinding a tool of the diameter oi tool 5, The screw 19 is turned to swing the toolholders member and thus offset the axis 30 (see Fig. 5) of the tools operative rotation from the axis 31 of the swingable mounting 11 of the tool-holders support 10, sufficiently to provide the desired clearance for the outward faces 32 of the flutes. The screw stop 16 is turned to limit the swinging movement of the block 12 and the parts carried thereby (including the tool) toward the grinding wheel, in order to provide the desired degree of the taper of the tools forward end. The tool is now turned on the mandrels by hand so as to bring each flute to the position shown by flute 33 in Fig. 5, in which position the tool is held by the stop spring as against rotation in the opposite direction. The tool-holders support 10 is now swung on the axis 31 of its pivotal mounting 11 by the supports handle portion 34, suiliciently to grind off the portion 35 of the flute and thus provide the convex clearance 36, between the tool and its work extending increasingly from the flutes cutting edge 37, as shown in the flutes 38 and 89. After all the flutes are thus ground, the screw stop 16 may be loosened slightly and the operation repeated, whereby the outward faces of the flutes are ground to a slightly additional degree and a perfectly finished product is attained. To grind taps having left-hand threads the bracket 26 is turned half way around 011 the bar 22, and the rod 25 is so adjusted as to cause the extremity of the spring 24 to engage the side of the flute adjacent the cutting edge of such a tool; the pin 40 is also withdrawn from its socket di and inserted in its other socket 42, thus limiting the swinging movement of the support 10 between the stops 43 and 4A.

In Fig. 6, the periphery of the grinding wheel engages the tool, instead of its side engaging the tool as in Fig. l. The parts however are essentially the same in both constructions. In Fig. 6 the outer end of the tool is clamped between jaws 45, 46 pressed into such clamping engagement by a nut 47.

It will be seen that by my machine the flutes are all uniformly tapered and the same clearance is provided for each.

The axis 31 of the tool-holders swinging movement, being produced, intersects the tools transverse planes which intersect its surface being ground.

The invention being intended to be pointed out in the claims, is not to be limited by or to the details of construction of the par ticular embodiment thereof illustrated by the drawings or hereinbefore described.

I claim:

1. In a machine for tapcringly grinding the outward faces of the flutes of a laterallycutting rotary tool; agrinding wheel; a tool-holder adapted to hold the tool in such position that its axis of operative rotation is inclined relatively to the grinding surface of the wheel and its cutting side is presented tiereto, the tool-holder being swingably mounted on an axis offset from the tools said axis and as produced intersecting the held tools transverse planes which intersect its surface being ground.

2. In a machine for taperingly grinding the outward faces of the flutes of a laterallycutting rotary tool; a grinding wheel; a tool-holder adapted to hold the tool in such position that its axis of operative rotation is inclined relatively to the grinding surfare of the wheel and its cutting side is pre sented thereto, the tool-holder being swingably mounted on an axis adjustably offset from the tool s said axis and as produced intersecting the held tools transverse planes which intersect its surface being ground.

In a machine for taperingly grinding the outward faces of the flutes of a laterally cutting rotary tool; a grinding wheel; a tool-holder adapted to hold the tool turnably on the axis of its operative rotation and in such position that its said axis is inclined relatively to the grinding surface of the wheel and its cutting side is presented thereto, the tool-holder being swingably mounted on an axis offset from the tool's said axis and produced intersecting the held tools transverse planes which intersect its surface being ground.

a. In a machine of the character de scribed; a grinding wheel: a block mounted swingably toward and away from the wheel; a tool-holder support mounted on the block swingably on an axis transverse to the bloclrs axis of swinging; a tool-holder carried by said support and adapted to hold a rotary tool in grinding relation with the wheel in a position wherein the axis of said supports swinging is offset from the axis of the tools operative rotation.

In testimony whereof I have hereunto set my hand at Grand Rapids Michigan this 5th day of March, 1920.

JACOB DE KUNING. 

